AW: [U-Boot-Users] SED13806 and MPC866

Wolfgang Denk wd at
Tue Aug 5 16:38:23 CEST 2003

In message <MFEGIPJEFHIKHGDLDACIKEOICAAA.marco.schramel at> you wrote:
> Thanks for your reply.
> Does the Linux kernel not use the u-boot functions like a bios ? Sorry for
> that dummy newbie question.

Yes, it does. Exactly the same way. The coincidence is in  NOT  using
any such stuff.

Linux does not use any BIOS functions, and Linux  does  NOT  use  any
U-Boot  code.  Once  Linux starts, the U-Boot image is gone (as Linux
will claim all RAM thus deleting any U-Boot code that's there).

> I tell you my level of awarness.
> 	- First i have to fit the u-boot for my board
> 	- then i arrange my Linux kernel for my board
> 	- i load my Linux down

Rigth so far.

> 	- my Linux works with functions of u-boot and therefore my Linux kernel
> have to know which interfaces exists

Wrong. U-Boot performs certail initialization of the  hardware  (like
setting  up the memory controller), and when U-Boot passes control to
Linux, it  gives  it  a  few  parameters  (like  memory  size,  clock
frequencies, etc.). The U-Boot is gone forever, and Linux is running.
Linux cannot use any U-Boot code, and does not need to.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at
[Braddock:] Mr. Churchill, you are drunk.
[Churchill:] And you madam, are ugly.  But I shall be sober tomorrow.

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